To expand the expression \(-\frac{5}{6}(9b - 12)\), you distribute \(-\frac{5}{6}\) to both terms inside the parentheses.
Starting with the first term:
\[ -\frac{5}{6} \cdot 9b = -\frac{5 \cdot 9}{6} b = -\frac{45}{6} b \]
This can be simplified to:
\[ -\frac{45}{6} b = -\frac{15}{2} b \quad \text{(dividing numerator and denominator by 3)} \]
Now for the second term:
\[ -\frac{5}{6} \cdot (-12) = \frac{5 \cdot 12}{6} = \frac{60}{6} = 10 \]
Putting it all together, we get:
\[ -\frac{5}{6}(9b - 12) = -\frac{15}{2}b + 10 \]
So the expanded expression is:
\[ -\frac{15}{2}b + 10 \]